A digital camera is commonly used as an imaging apparatus which converts a picture image taken by an imaging device into digital signals and records the signals on a recording device such as a nonvolatile recording medium. A personal computer is a typical example of an external apparatus capable of being directly connected to a digital camera via communication cable, etc. There are, other than personal computers, function-specialized types of external devices having only specific functions desired by users which are configured to be directly connected to a digital camera and recently the number of such kind of external devices is on the increase.
A printer is a typical example of the function-specialized types of external devices to which a digital camera is connected. Such printer is configured to be directly connected to a digital camera through a communication cable and read out a data file of a picture image (hereinafter, “image file”) from a recording medium with a build-in digital camera to print out the read-out image file. This print function performed by a digital camera and a printer capable of being directly connected each other is referred to as a direct print function.
There are a lot of inventions relating to a digital camera having the direct print function (e.g. JP11-88815A, JP11-146311A, JP2000-232617A). Each invention has an improvement in a method of a print process. An example of a picture image print process carried out by a digital camera having a common direct print function is described below referring to a flowchart in FIG. 14. In FIG. 14, each step is represented by “201”, “202” . . . .
When a digital camera is connected to a printer via a communication cable to be in a state in which communication is enabled (Step 201), the digital camera requests the printer to transmit information representing the printer's capability of performing processes (hereinafter, “printer capability value”) (Step 202). In accordance with the request the printer transmits its own printer capability value to the digital camera (Step 203). The digital camera receives the printer capability value transmitted from the printer (Step 203) and displays available capability items according to the information stored in the received printer capability value on a display device of the digital camera (Step. 205). The “capability items” mean information indicating process contents able to be selected with the digital camera and the information visually displayed on the display device allows to a user to select process contents optionally.
An example of a printer capability value transmitted from the printer to the digital camera and an example of a display of capability items based on the printer capability value are shown in FIGS. 15A and 15B, respectively. FIG. 15A shows the example of the printer capability value. As shown in FIG. 15A, the printer capability value is a script file described in accordance with a predetermined format, including an information identifier 30 indicating that the file represents the printer capability value, an item information identifier 31 indicating capability items which are able to be processed by the printer, and capability item group 32 indicating each capability which a user can select.
FIG. 15B shows an example of an operational selection screen displayed by the digital camera according to the printer capability value. As shown in FIG. 15B, the screen 130 is provided with a screen title display portion 130a and an operational menu display portion 130b. The digital camera previously stores in its internal storage portion data for display in accordance with the capability item group 32 described in the printer capability value. Accordingly, the data for display in accordance with the capability items described in the printer capability value are read out and converted into a screen image in an information format in which the user can easily confirm them and the screen image is displayed.
Referring to FIG. 14, when the user determines desired picture images after she/he selects a capability item on the operational selection screen (Step 206) and then a print request process is carried out through an operation of the digital camera, the digital camera generates and transmits a print request information file to the printer (Step 207). The printer which received the print request file requests the digital camera to transmit the image files to be printed out described within the print request information file and the digital camera transmits to the printer the image files requested to be sent (Step 208). The printer generates and prints out output data with use of the received image files, and transmits result information whether the print process is completed normally or erroneously to the digital camera. If the result information indicates an erroneous completion of the print process, the digital camera terminates the print process (“No” at Step 209). If the print process is completed normally (“Yes” at Step 209), the digital camera judges whether the print process for all image files previously selected is completed or not, and if any unprinted image file exists, the process is repeated from Step 207 (“No” at Step 210).
As described, in order to carry out a specific process desired by a user in the above-explained print process, a corresponding operation to the digital camera is required. To carry out such operation a printer capability value transmitted from the printer need be displayed as visible information. In the case where information to which the digital camera side cannot reply is included in information described in the printer capability value due to extended functions of the printer, corresponding items cannot be displayed.
If an exclusive display data for all printer capability values to which the digital camera cannot reply is set in advance, it can be avoided that nothing is displayed when the digital camera receives such printer capability value. However, according to this setting, a user can hardly understand what kind of process is carried out by an operation.